Mixture fraction analysis of combustion products in medium-scale pool fires

A mixture fraction analysis is performed to investigate the characteristics of time-averaged gaseous species measurements made along the centerline of medium-scale pool fires steadily burning in a quiescent environment. A series of fire experiments are conducted using 30 cm diameter liquid and 37 cm diameter gas pool burners. All gaseous species measurements are extracted at various heights within the fire and analyzed using an Agilent 5977E Series Gas Chromatograph with mass selectivity and thermal conductivity detectors. Soot mass fractions are simultaneously measured during gas sampling. For all fuels, the results show that the local composition plotted as a function of mixture fraction collapses the experimental data into a few coherent lines that nearly match the idealized reactions. Differences between the theoretical and experimental data are attributed to the presence of carbon monoxide, soot, and other intermediate carbon-containing species. The ratio of carbon monoxide and soot is presented as a function of mixture fraction in which a trend is observed. Published by Elsevier Inc. on behalf of The Combustion Institute.